Amongst the new Fire Phone's most rumored and anticipated features is a "3d effect" which Amazon calls "Dynamic Perspective." It moves around as you tilt the phone, altering the image in front of you in different ways depending on the app you're using.

What does it do?

Before explaining how the actual technology works, Jeff Bezos gave us a number if examples of how it might be used. Dynamic Perspective can used for a host of one-handed gestures so that you can scroll through a web page or page through a book without ever tapping your phone.

In one case, Bezos showed how by simply tilting the phone you could scroll through a carousel of images. A light tilt moves the carousel slowly; a harder tilt gives you more of a flipbook effect. The speed of the gesture is applicable to scrolling as well.

Perhaps the most striking example of the technology in action was in maps, where a 3D overhead view of the Empire State building moved around as the phone moved around. Meanwhile flicks added and removed layers of information.

Overall, the implementations seemed slick when used by a seasoned operator, but on the other hand they could become very confusing to the casual user.

How does it work?

The key as Jeff Bezos explains, isn't so much using the built-in gyroscope or accelerometer, but instead keeping track of where your face is at all times with cameras.

In addition to the front-facing camera, which only has a 72-degree field of view, Amazon developed new wide angle cameras with 120-degree field of view. The phone needs to use more than one camera in order to know both X, Y, and, Z directions. At any given time, the Fire Phone is only using two of the four cameras. And for situations when it's two dark for the visible light camera to work, each of the cameras have a built-in infrared LEDs. According to Amazon the cameras are "ultra-low power" and use their on dedicated processor.

As with the Firefly visual recognition technology, Amazon's Dynamic Perspective SDK will be available to third party developers so that they can build out their own applications for the technology.

In short, Amazon has developed some incredible tech, but it'll be up to the strength of the software that's developed using Dynamic Perspective to match the potential. It's definitely impressive—whether it's a worthwhile experience is another question altogether.